Fig. 1From: Diagnostic value of contrast-enhanced ultrasonography in the preoperative evaluation of lymph node metastasis in papillary thyroid carcinoma: a single-center retrospective studyFlowchart of this retrospective study. PTC, papillary thyroid carcinoma; cN0, clinical-node negative; cN1, clinical-node positive; cN1a, clinical central node positive; cN1b, clinical lateral node positiveBack to article page